Messages in this thread | | | Date | Thu, 18 Jul 2002 01:22:38 -0700 | From | William Lee Irwin III <> | Subject | Re: [RFC] BH removal text |
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On Sun, Jul 14, 2002 at 10:22:19AM +0530, Dipankar Sarma wrote: > Even if you replace timemr_bh() with a tasklet, you still need > to take the global_bh_lock to ensure that timers don't race with > single-threaded BH processing in drivers. I wrote this patch [included] > to get rid of timer_bh in Ingo's smptimers, but it acquires > global_bh_lock as well as net_bh_lock, the latter to ensure > that some older protocol code that expected serialization of > NET_BH and timers work correctly (see deliver_to_old_ones()). > They need to be cleaned up too. > My patch of course was experimental to see what is needed to > get rid of timer_bh. It needs some cleanup itself ;-)
It turns out those profiling results are total garbage. oprofile hit counts during the tbench 1024 run with smptimers-X1 on the 16-way 16GB NUMA-Q follow:
c020249d 43051806 73.9493 .text.lock.dev c0196750 2138900 3.67395 csum_partial_copy_generic c020090c 1454023 2.49755 netif_rx c0200e78 1237550 2.12572 process_backlog c0200480 1083695 1.86144 dev_queue_xmit c0120bf8 1013839 1.74145 run_timer_tasklet c0228c8c 946933 1.62653 tcp_v4_rcv c0196920 773495 1.32862 __generic_copy_to_user c012009c 605591 1.04021 mod_timer c01fbe98 477906 0.820891 sock_wfree c0218e14 392831 0.674759 tcp_recvmsg c0112648 362804 0.623182 try_to_wake_up c01132fc 278976 0.479192 schedule c0136087 251550 0.432083 .text.lock.page_alloc c0211d14 215139 0.36954 ip_queue_xmit c021759c 205078 0.352259 tcp_sendmsg c0220ad4 203218 0.349064 tcp_rcv_established c0112f64 189216 0.325013 scheduler_tick c02221a4 187313 0.321744 tcp_transmit_skb c021f5fc 184471 0.316863 tcp_data_queue c02189a8 163828 0.281404 tcp_data_wait c01dd820 139310 0.23929 loopback_xmit c01fcfcc 137241 0.235736 skb_release_data
I'll follow up with the "before" profile next.
Cheers, Bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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